It has long been known in the disposable absorbent article art that it is extremely desirable to construct absorptive devices such as disposable diapers, catamenials, sanitary napkins, bandages, incontinent briefs, and the like, presenting a dry surface feel to the user to improve wearing comfort and to minimize the development of undesirable skin conditions due to prolonged exposure to moisture absorbed within the article.
One commercially used solution to the aforementioned problem is the use of a nonwoven web as a topsheet on a disposable absorbent article. The nonwoven web topsheet provides a soft surface in contact with the users skin. Moisture deposited on the nonwoven topsheet is transmitted through the openings between the fibers and into the absorbent core. However, because of the randomness of the fibers within the nonwoven topsheet, some moisture tends to hang up or collect within the nonwoven creating an undesirable condition as the skin is exposed to the moisture within the nonwoven.
Another solution to the aforementioned problem is disclosed in commonly assigned U.S. Pat. No. 4,342,314 issued to Radel et al. on Aug. 3, 1982 and hereby incorporated herein by reference. Radel et al. discloses an absorbent article with a wearer-contacting topsheet comprising a resilient, macroscopically expanded, three-dimensional plastic web exhibiting a combination of fiber-like and plastic properties. In a preferred embodiment, the macroscopically expanded, three-dimensional plastic web topsheet disclosed in Radel et al. exhibits a fine-scale three-dimensional microstructure comprising a regulated continuum of capillary networks, of steadily decreasing size, originating in and extending from one surface of the web and terminating in the form of apertures in the opposite surface thereof to promote rapid fluid transport in the direction of decreasing capillary size. The web's fiber-like appearance is comprised of a continuum of fiber-like elements, the opposed ends of each of the fiber-like elements being interconnected to at least one other of the fiber-like elements. A typical capillary network in the Radel et al. structure comprises an uppermost capillary opening or aperture formed by a multiplicity of primary fiber-like elements interconnected to one another in the uppermost plane of the web. The uppermost opening may, if desired, be further subdivided into smaller capillary openings by secondary and tertiary fiber-like elements at planes located below the wearer-contacting surface of the web. Each of the fiber-like elements exhibits a substantially uniform U-shaped cross-section along its length. In the case of a primary fiber-like element, its cross-section comprises a base portion located in the wearer-contacting plane and a sidewall portion joined to each edge of the base portion and extending generally in the direction of the absorbent pad-contacting surface of the web. The sidewall portions which intersect one another are joined to one another intermediate the wearer-contacting surface and the absorbent pad-contacting surface of the web, thereby forming a capillary network interconnecting the opposed surfaces of the web. The secondary and tertiary fiber-like elements, when employed, are generally similar, but originate in planes below the wearer-contacting surface of the web.
One drawback associated with the use of topsheets comprised of plastic is that despite their superior fluid handling characteristics some users are very reluctant to place a topsheet which they readily perceive as plastic by virtue of its glossy appearance in contact with their skin.
To reduce the gloss on the web's visible surface, i.e., that portion of the web which is visible from directly overhead, it has been learned that inclusion of a microscopic pattern of surface aberrations which are not discernible when the perpendicular distance between the viewer's eye and a plane of the web is about 12 inches is highly effective. Commonly assigned U.S. Pat. No. 4,463,045 issued to Ahr et al. on Jul. 31, 1984 and hereby incorporated herein by reference, s defines the relevant criteria which must be satisfied so that the three-dimensionally expanded web will exhibit a substantially non-glossy visible surface. The topsheet of the type generally disclosed in Radel et al., having surface aberrations according to Ahr et al., exhibits a fiber-like appearance and tactile impression as well as a non-glossy visible surface. In addition, it is highly effective in promoting rapid fluid transfer from the first or wearer-contacting surface to the second or absorbent pad-contacting surface of the topsheet. Topsheets of the latter type have enjoyed wide spread commercial success on catamenial pads due to their clean and dry appearance in use when contrasted to conventional nonwoven fibrous topsheets.
While nonwoven topsheets and plastic topsheets of the type generally disclosed in Radel et al. and Ahr et al. have enjoyed widespread commercial success, it will be readily appreciated that even further improvements in clean and dry appearance in use are highly desirable in products of this type.